The invention relates to an airport in-pavement lighting fixture.
Light fixtures for airport runways and taxiways often are recessed into the pavement to delineate the outer boundaries of the runway or taxiway and to provide a visual indication of the location of the runway or taxiway. Such a light fixture installation typically includes a transformer, a base assembly and a light fixture. The base assembly is positioned in the pavement and holds the transformer. The light fixture is removably positioned within the base assembly. The light fixture may include an optical housing, a bottom cover, a lamp bracket assembly and a lamp. Typically, the optical housing and the bottom cover together define a watertight housing that contains the lamp bracket assembly and the lamp.
To replace a lamp that has burned out, the light fixture is removed from the base assembly using a special tool or set of tools. Then, an electrical connection between the transformer and the light fixture is disconnected. The light fixture then may be taken from the runway to the maintenance shop where the light fixture is disassembled by removing screws that retain the optical housing to the bottom cover to take the optical housing off of the bottom cover. With the bottom cover removed, the lamp is removed from the lamp bracket assembly in which it is positioned during use, and a new lamp is inserted. Next, the lamp assembly is reassembled in the reverse order, while ensuring that a gasket, which provides a seal between the bottom cover and the optical housing, is in good condition. The gasket must be replaced if it has deteriorated sufficiently that it will not provide a sufficient seal. After the light fixture is reassembled, it is reconnected to the transformer and repositioned in the base assembly.
In one general aspect, an in-pavement airport lighting fixture includes a housing, a feed-through assembly for carrying a lamp and positioning the lamp in the housing, and a threaded bolt extending through the housing for securing the housing to a base unit. The threaded bolt is coupled to the housing such that the housing is lifted by upward motion of the bolt as the bolt is disengaged from the base unit. The housing further includes at least one boss and the feed-through assembly includes a connector surrounding an upper portion of the feed-through assembly. The connector mates with an outer surface of the boss when the upper portion of the feed-through assembly is positioned against an inside surface of the boss.
Embodiments may include one or more of the following features. For example, the housing may include an optical housing that mates with a bottom cover. The bottom cover includes a flange having a first mating surface that mates with a second mating surface of the optical housing. The first mating surface includes a groove having a gasket disposed in the groove. The gasket may be formed from an elastomer. The gasket may be bonded to the groove with an adhesive. The gasket may be configured to form a moisture barrier and a vibration damping mechanism when the first mating surface is mated to the second mating surface.
The housing may include an optical housing and a bottom cover formed as one piece.
The base unit may be mounted in the ground and include a transformer to supply power to the lamp. The base unit may be a retaining base or a mounting ring.
The in-pavement airport lighting fixture may further include at least one retaining clip and the bolt may include a head and a shaft that includes a bearing, with the retaining clip encircling the shaft. The housing may include at least one bolt hole such that the bolt passes through the bolt hole and the retaining clip encircles the shaft between the bearing and the head. The bearing may be positioned on the shaft between an upper portion and a lower portion of the shaft such that the retaining clip is inserted around the upper portion of the shaft.
The lower portion of the shaft may be threaded and the in-pavement airport lighting fixture may further include a retaining base having at least one threaded bolt hole. The threaded lower portion of the shaft may be threadably mated with the threaded bolt hole to mate the retaining base with the bottom cover.
The retaining clip may have an inner diameter less than an outer diameter of the bearing.
The boss may include at least one hole in the outer surface with a pin disposed in the hole. The connector may include a slot on an inside surface of the connector such that the pin is inserted into the slot when the connector is mated with the outer surface of the boss.
The in-pavement airport lighting fixture may further include second and third holes in the outer surface of the boss, second and third pins disposed in the second and third holes, and second and third slots in the inside surface of the connector. The second and third pins are inserted into the second and third slots when the connector is mated with the outer surface of the boss.
The boss may include an aligning pin protruding from the inner surface of the boss and the feed-through assembly may include an aligning slot. The aligning pin mates with the aligning slot when the connector is mated with the outer surface of the boss.
The slot may be aligned in a helical direction of the connector and may terminate at an opening passing through the connector. The pin passes through the slot and into the opening when the connector is mated with the outer surface of the boss.
In another general aspect, a method of installing an in-pavement airport lighting fixture includes providing an in-ground base unit, providing a housing, providing a feed-through assembly for carrying a lamp and positioning the lamp in the housing, and positioning the feed-through assembly in the housing. The housing includes at least one boss and the feed-through assembly includes a connector surrounding an upper portion of the feed-through assembly. The connector mates with an outer surface of the boss when the upper portion of the feed-through assembly is positioned against an inside surface of the boss.
Embodiments may include one or more of the following features. For example, the method may further include providing a threaded bolt, extending the threaded bolt through the housing, and securing the housing to the base unit. Securing the housing to the base unit includes engaging the threaded bolt to the base unit. The threaded bolt lifts the housing by upward motion of the bolt when disengaging the bolt from the base unit.
The method may further include providing a bottom cover, providing an optical housing, providing a gasket, and mating the bottom cover with the optical housing to form the housing. The bottom cover includes a flange having a first mating surface that mates with a second mating surface of the optical housing. The first mating surface includes a groove having the gasket disposed in the groove.
Another general aspect includes a method of changing a lamp in an in-pavement airport lighting fixture. The fixture includes an in-ground base unit, a housing, a threaded bolt extending through the housing to secure the housing to the in-ground base unit, and a feed-through assembly for carrying the lamp and positioning the lamp in the housing. The method includes disengaging the threaded bolt from the base unit. The threaded bolt lifts the housing by upward motion of the bolt when disengaging the bolt from the base unit.
Embodiments may include one or more of the following features. For example, the method may further include removing the feed-through assembly from the housing and replacing the lamp. The method may still further include positioning the feed-through assembly in the housing, extending the threaded bolt through the housing, and securing the housing to the base unit. Engaging the threaded bolt to the base unit secures the housing to the base unit.
The in-pavement runway light fixture provides considerable advantages, such as the ability to more easily perform maintenance on the fixture. For example, the bolts and retaining clips allow maintenance personnel to remove and install the bottom cover and optical housing without the use of special tools. Because the bolts and retaining clips remain attached to the bottom cover and optical housing when removed from the retaining base, there is little likelihood of losing the bolts and retaining clips.
Mounting the gasket in the groove in the flange eliminates the need to change the gasket every time the bottom cover is removed from the optical housing. This reduces the costs associated with labor and materials because the gasket must be replaced only when severely damaged. The gasket provides a moisture barrier and vibration damping, which improve the longevity of the light fixture.
The quick-disconnect, feed-through assembly reduces the time needed to replace faulty lamps because the assembly can be removed, and the lamp replaced, at the runway without the need to take the bottom cover and optical housing to a maintenance facility. The design of the feed-through assembly also provides the advantage that after reinstallation the lamp and reflector are aligned in the correct direction because of the mating of the keyed slot and pin.